Voyager 1 Has Officially Left Our Solar System
NASA have just announced that their spacecraft, Voyager 1, is officially the first interstellar craft in our history. According to recent data, Voyager 1, which was launched in 1977 has unequivocally travelled beyond the boundaries of our solar system after 36 years of travel. Equally astonishing is that the new findings suggest it has actually been in interstellar space for almost a year.
The boundaries of our solar system are defined by the effects of our sun, known as the heliosphere. For some time now, it has been debated as to whether or not the Voyager 1 spacecraft has passed through the heliosphere and therefore into interstellar space. Now, new data show that Voyager 1 is in an almost completely different environment, thus marking its official passing through the heliosphere.
The changes in the spacecraft's environment that are being referred to are the levels of plasma surrounding the craft. Within our solar system, plasma is indeed present, however outside the heliosphere, plasma is far more dense. Voyager 1 doesn't actually have a plasma sensor, which is one of the reasons it has been so tricky to define exactly whether or not it had left our solar system, but when a coronal mass ejection occurred in 2012, NASA scientists had the opportunity they were waiting for...
The effects of a coronal mass ejection on the particles within our solar system are well known; it causes them to vibrate as the magnetically charged particles shoot out from the sun and off into space. So when Voyager detected a significantly different level of particle oscillations, scientists seized the moment to analyze the plasma levels around the spacecraft. What they found was cause for massive celebrations. They found that Voyager 1 was surrounded by plasma at a density more than 40 times of that which can be found inside our solar system. They were finally able to prove that Voyager 1 has left building.
Voyager 1 has traversed our solar system, passing beyond Mars, through the asteroid belt and beyond the gas giants of our outer solar system. It is currently a staggering 19 billion miles from its point of origin and still going strong. It will forever be marked in human history for it's feats to date, but many feel that it still has much, much more to offer us. So, for this plucky little spacecraft, the best may well be yet to come.